The present invention relates in general to cellular telephone handsets, and, more specifically, to slider phones having extendable parts to increase the form factor during usage of certain functions of the handset.
A popular form factor for wireless handsets including mobile cellular phones is the slider phone. A typical slider device has two separate housing sections that slide relative to each other to thereby change the size of the handset along at least one dimension between a configuration for storage or standby and a configuration for active usage involving particular functions of the handset. The housing sections can slide linearly or may rotate at various pivot points. When the slider is extended for use as a phone, the distance between the microphone and speaker of the handset is increased to better match the distance between the ear and mouth of the user. In addition, a keypad or other elements of a user interface may be uncovered for access when the housing sections are extended. Thus, certain keys may be hidden when the handset is in the closed configuration so they are protected from accidental activation when the handset is in standby. Typically, the user keeps the handset in the closed configuration for carrying in a pocket or purse and places the handset in the extended configuration in order to use it as a phone, personal digital assistant (PDA), or a camera, for example.
A problem sometimes experienced with the slider form factor is unintentional closing of the handset while intending to continue to use a desired function. For example, when the handset is being used as a wireless phone and it is being held in one hand by the user while attempting to perform other manual tasks such as opening a door or lifting some item with the other hand, the user can easily mishandle the handset to accidentally apply a closing force on the sliding components which may deactivate (i.e., hang up) the phone function. Even if the handset design is such that the call continues when the slider is closed or partially closed, its effectiveness would still be reduced since the microphone and speaker are no longer held at an optimal distance. Likewise, other functions being performed on a slider phone are best performed with the slider fully open. For example, a camera lens for a camera phone may be located on a surface of the housing which is covered when the slider is closed, thereby providing protection of the camera lens when the handset is not in use. Accidental closing or partial closing of the handset while using the camera function could ruin the capture of a photograph. In another example, a keypad or keyboard may extend from a covered configuration in order to use text-based communication functions such as email and SMS text messaging. Accidental closure of the housing sections while using any of these functions interferes with the performance of the functions. Thus, it would be desirable to reduce the chance of accidental closures while particular functions of the wireless handset are being actively used.